High-strength permeable wall blocks: an innovative solution to solve urban waterlogging and heat island effect
Publish Time: 2025-05-06
At a time when urbanization is accelerating, the decline in rainwater retention capacity and the intensification of the heat island effect caused by traditional hard pavement are becoming key issues restricting the sustainable development of cities. A new wall blocks material made of crushed stone and cement composite pressing provides a solution with both mechanical properties and ecological benefits for sponge city construction through material innovation and structural optimization.The core advantage of this wall blocks comes from its breakthrough material ratio and molding process. By precisely controlling the ratio of crushed stone grading and cement matrix, combined with high-frequency vibration pressurization molding technology, the compressive strength of the product exceeds the 45MPa mark and reaches the C45 concrete standard. This strength characteristic enables it to withstand repeated rolling by heavy vehicles and show excellent durability in high-load scenarios such as municipal roads and logistics parks. The measured data of a logistics center in Beijing showed that two years after the wall blocks were laid, the surface wear rate was only 0.3%, far lower than the 1.2% of ordinary permeable bricks.In terms of water permeability, wall blocks adopt a three-dimensional through-pore structure design, with a reasonable porosity of 20%-30%, to build an efficient rainwater infiltration channel. The unique rough particle structure on its surface not only increases the rainwater infiltration rate by 40%, but also increases the anti-slip level to R12 (DIN51130 standard) by increasing the friction coefficient of the contact surface. This feature is particularly critical in rainy and snowy weather - after the renovation of a commercial street in Shanghai, the pedestrian slip accident rate in rainy days decreased by 87%, and the ice area in winter decreased by 92%, effectively ensuring public safety.The realization of ecological functions is due to the multi-level water retention mechanism of wall blocks. During heavy rainfall, its internal pores can quickly store rainwater, and the water storage capacity of a single wall block reaches 8.5L/m², which is equivalent to forming a temporary water storage layer with a thickness of 17mm. These water are slowly released into the soil through capillary action, providing a continuous water source for green belt plants. The practice of an ecological community in Nanjing shows that after laying the wall blocks, the frequency of green belt irrigation has been reduced from 3 times a week to 1 time a week, and the water saving rate has reached 65%. In the dry season, the evaporative cooling effect reduces the surface temperature by 5-8℃ compared with traditional paving. Combined with the "cold island effect" formed by large-scale paving, the surrounding environment temperature can be reduced by 2-3℃.From the perspective of system benefits, the wall blocks show multi-dimensional value in the construction of sponge cities. Its permeable and water-retaining characteristics reduce the rainwater runoff coefficient from 0.9 to 0.3, and under the condition of a 50-year heavy rain, it can reduce the regional flood peak flow by 35%. After application in a new district in Shenzhen, the waterlogging time was shortened from an average of 4.2 hours to 0.8 hours, and the load of the drainage network was reduced by 40%. At the same time, the production of wall blocks adopts construction waste recycled aggregate technology, and each ton of product can consume 0.6 tons of waste concrete, achieving a resource recycling rate of 85%, which is in line with the concept of "zero-waste city" construction.At the construction application level, the wall blocks show good engineering adaptability. Its modular design supports dry paving, and its construction efficiency is three times higher than that of traditional processes, and it can be disassembled and reassembled at any time. In the renovation of an old community in Hangzhou, this technology was used to complete the renewal of 3,000 square meters of road surface in just 7 days, shortening the construction period by 60% compared with conventional solutions. The later maintenance cost is also significantly reduced - 95% of the permeability can be restored by flushing with a high-pressure water gun, and the annual maintenance cost is only 1/3 of that of permeable concrete.In the face of extreme weather challenges brought about by climate change, this high-strength permeable wall blocks has built a sponge city technology closed loop of "seepage, stagnation, storage, purification, use, and discharge" through material innovation and system optimization. It not only solves the pain points of urban waterlogging and heat island effect, but also provides a replicable technical paradigm for urban sustainable development through resource circulation and ecological services. With the advancement of the "dual carbon" goal, this type of new building material that is both functional and ecological will surely play a greater role in urban renewal.
